What causes the car not to idle when cold but fine when warm. When you first on 1994 Geo Prizm

Crank it you have to two foot it, its like the choke not picking up but once it warms up it is fine please help teenage daughters car

1 answer 4 comments
Light on in dash? Needs to be scanned, possible coolant tempture sensor reading incorrectly. Needs to be scanned!!
No lights on ,temp gauge does read a little cooler than her other one she had a 96
Scanner will read the signal from the sensor to see if it's right plus other live data can be read to help determine the problem. Cant guess at it,, wont help! The coolant temp SENSOR is not the same as the tempture SENDING unit for the gauge! It tells the computer what ambient tempture is and if the reading is wrong, so will be the amount of fuel sent to the engine! It is basically the choke as we know it.
Oh Ok so even if there's no light on, the computer could b getting a reading of some sort, didn't realize the temp could effect idle, I'm old school simple Chevrolet's, will take & have scanned hope tells me something , if I know what's wrong I can fix , thanks so much will let u know the outcome
You welcom. Yeah,the sensor can be out of range and not turn on the light! Best way to check it is with a scanner hooked up while engine is cold, it should read ambient tempture, just like a thermometer. Now a parts store cant SCAN test it,,they can only read codes, but cant even do that on this vehicle anyway. NAPA part # for the sensor is TS6677SB.